C_f/SiC复合材料抗氧化涂层的制备、性能与保护机理  

PREPARATION, PROPERTIES AND PROTECTION MECHANISM FOR OXIDATION RESISTANT COATINGS OF C_f/SiC COMPOSITES

作　　者：邹世钦[1] 张长瑞[1] 周新贵[1] 曹英斌[1] 

机构地区：[1]长沙国防科技大学航天与材料工程学院

出　　处：《硅酸盐学报》2005年第7期811-816,共6页Journal of The Chinese Ceramic Society

基　　金："863"计划(2002AA305102);国防预研基金(41312011002)资助项目。

摘　　要：用化学气相沉积法(chemicalvapordeposit,CVD)在碳纤维增强碳化硅复合材料(carbonfiberreinforcedsiliconcarbidecomposites,Cf/SiC)表面制备了CVDSiC粘接层、自愈合功能层和CVDSiC耐冲蚀层组成的3层涂层体系,并进行了氧化实验。结果表明:单层CVD SiC涂层保护试样的氧化质量损失速率比无涂层试样的明显降低,含有自愈合层的3层涂层保护试样比单层CVDSiC保护试样的氧化质量损失速率又有明显降低。3层涂层保护的试样800～1300℃的氧化质量损失率非常小,氧化288h后仍能保持较高的弯曲强度。通过扫描电镜观察到自愈合层的玻璃态物质进入涂层裂纹中,有效地填充裂纹并阻挡氧的通过。同时,因涂层不均产生的孔洞或玻璃态物质流失后产生的涂层裂纹等缺陷会导致其自愈合功能的失效,使Cf/SiC复合材料不均匀氧化。A oxidation resistant coating system with 3 layers including a chemical vapor deposition (CVD)SiC bonding layer, self-sealing active layer and CVDSiC erosion resistant layer was prepared on carbon fiber reinforced silicon carbide(C_(f)/SiC) composites. Oxidation tests were carried out in static atmosphere. Results of the oxidation tests indicate that the samples with CVDSiC coating alone have less mass loss than that without coating, and the samples with three layers of coatings have less mass loss than that with only CVDSiC coating .The samples with a self-sealing active layer have little mass loss and retain high bending strength after oxidation in atmosphere for 288 h from 800 ℃ to 1 300 ℃. Scanning electron microscope photographs indicate that vitreous material of the self-sealing layer fills in cracks of the coating, resulting in blocking off the passage of oxygen efficiently. However holes and cracks produced from inhomogeneous coatings may cause the self-sealing layer to malfunction, which brings a local oxidation and invalidation of C_(f)/SiC composites.

关 键 词：抗氧化涂层 碳纤维增强碳化硅复合材料 氧化实验 自愈合功能 

分 类 号：TB323[一般工业技术—材料科学与工程]